In Tolkien's cosmology, Arda (the Earth) is at first created without the Sun and Moon to illumine it, and its earliest history is measured in Valian Years (V.Y.). After the creation of the Trees of the Valar, a new tally of Years of the Trees is begun in V.Y. 3501. In about V.Y. 4550, at the First Age of the Children of Ilúvatar begins with the Awakening of the Elves.

Tolkien revised his chronology numerous times. The Annals of Valinor were written in the early 1930s. In this early version, a Valian Year corresponds to 10 solar years, and the time from the creation of Arda until the creation of Sun and Moon is 3,000 Valian Years. In a revision dated c. 1937, the earlier timeline is mostly left intact, with the addition of the explicit statement that "It is said that the Valar came into the world 30,000 Sun-years ere the first rising of the Moon".

The chronology underwent major revisions after the publication of The Lord of the Rings, in about 1958. In this revision, published as the Annals of Aman, Tolkien defined a Valian Year as equal to 9.852 solar years, and the Valian Year of the creation of Sun and Moon was now given as 5000, so that the time between the creation of Arda and the rising of the Sun and Moon was now the equivalent of 47,910 solar years instead of 30,000.

Late in his life, Tolkien planned to again revise chronology, now assuming one Valian Year as the equivalent of 144 solar years. This is consistent with his earlier decision (published in 1955 in Appendix D of The Lord of the Rings) that the Elves would reckon time in "long-years" or yéni equivalent to 144 solar years (thus equating the yéni and the Valian Year), but Tolkien never finished this final revision.

Before the making of the Sun dates are given in Valian Years and not all events can be precisely dated. In such cases events are given in chronological order between known dates. Although all dates prior to the first sunrise have been given in Valian years, these can be converted to Years of the Lamps by subtracting 1900, Years of the Trees by subtracting 3500, or Years of the Trees in the First Age by subtracting 4550.

The conversion between Valian Years and Years of the Sun is not clear, depending on the choice of conversion factors (among many that Tolkien used at different times), the First Age may have lasted anywhere between 4,902 and 65,390 sun years. The greater number is supported by the Appendices to The Lord of the Rings and later writings, the lesser by earlier writings. In Morgoth's Ring, Christopher Tolkien cites a passage stating a Valian Year being "longer than are now nine years under the Sun."[2]

1: After many ages completing labours in the halls of Eä, including Varda's crafting of the stars, the Valar descended into Arda at the time of its origin.

First War: Melkor assaults his brethren and disrupts the ordered symmetry they seek to build within Arda.

1500: Tulkas arrives, the last of the Valar to descend into Arda: Melkor runs from him and hides in the halls of Eä.

The Valar begin their labours anew and order the lands and seas to their liking.

1900: The Two Lamps, Illuin and Ormal, are set upon pillars to provide light for Arda.

Ordering of Arda by the Valar. They form the isle of Almaren to dwell upon.

Spring of Arda: first forests grow, and non-humanoid animals are awakened.

Melkor's spies and secret friends, chief among them a great craftsman of the folk of Aulë, later named Sauron, inform him that the Valar are weary from their labours.

3400: Wedding of Tulkas and Nessa. Melkor returns in secret with followers from Eä and begins building Utumno.

Melkor begins to corrupt the lands and living things of Arda, turning them into sickly or monstrous shapes.

The Valar become aware of Melkor's return and begin seeking his stronghold.

3450: Destruction of the Two Lamps and the isle of Almaren by Melkor and his followers; Spring of Arda ends.

Melkor retreats to Utumno while the Valar save what they can from the cataclysm.

The Valar establish a new home in Aman and raise the Pelóri to defend it.

4615: The Elves reach the great river which would later be called Anduin. A group of Teleri under Lenwë (or Dan), wary of crossing the Misty Mountains, abandon the March near the Anduin and become the Nandor.

4649: Ulmo finally returns for the Teleri, but many stay behind because Elwë is not yet found, and become the Sindar. Another group remains behind at the request of Ossë, and together with those who came too late they become the Elves of the Falas under Círdan.

4651: The majority of the Teleri are ferried across on Tol Eressëa, which is anchored in the Bay of Eldamar. They take Elwë's brother, Olwë, as lord.

4652: Elwë awakes from slumber and reunites with the Sindar. He becomes known as Thingol, settling in Doriath.

4661: The Teleri of Tol Eressëa learn the art of shipbuilding, and ferry across the bay of Eldamar to Aman, where they found the city of Alqualondë.

4665: The last Vanyar abandon Tirion and settle in Valimar proper. The Noldor remain in Tirion under their lord, Finwë.

4990: Fëanor, deceived by Melkor, draws arms against his brother and is banished from Tirion: his father, Finwë, and many of the Noldor follow him in exile to Formenos.

4992: Fëanor argues with Melkor at Formenos. Melkor hides from capture by the Valar and joins forces with Ungoliant.

4995: The Darkening of Valinor. Manwë tries to heal the feud of the Noldor, and summons Fëanor to a festival in Valimar. Melkor and Ungoliant destroy the Two Trees, kill Finwë and steal the Silmarils. Fëanor becomes High King of the Noldor. Fëanor and his sons swear an oath to regain the Silmarils and the majority of the Noldor depart from Valinor; Noldor kill many Teleri and seize their ships in the First Kinslaying.

4996: Doom of Mandos: the Noldor are banished from Valinor and face great doom. Finarfin turns back and returns to Valinor.

4997: Melkor returns to Angband, and tries to take Beleriand: First Battle of Beleriand is fought; Denethor of the Green-elves slain and the Havens of the Falas are besieged. The Noldor arrive at Helcaraxë; Fëanor and his host betray the sons of Indis and sail across, then burn the ships at Losgar. Death of Amrod at Losgar. Return of the Noldor to Middle-earth. Morgoth's army attacks Fëanor. Dagor-nuin-Giliath ("the Battle under Stars") is fought. Fëanor is slain by Balrogs in sight of Angband. Maedhros becomes High King of the Noldor; he feigns to treat with Melkor, but is ambushed and taken captive. The Valar hide Valinor behind the Enchanted Isles and raise the Pelóri mountains to greater heights; they begin devising the Moon and Sun.

4998: Maedhros hung upon Thangorodrim. The Noldor camp around Mithrim, refusing to depart as Morgoth demanded

From this time on years are of normal length. Events from Valinor during the Years of the Sun cannot be accurately dated. All entries are derived from The Grey Annals (see references) unless otherwise noted. The dating begins anew at 1, although these years are still held to be part of the First Age.

1: The Sun first sets sail, start of reckoning by 'Years of the Sun', Awakening of Men in Hildórien.

60–c. 200: Melkor is absent from Angband, after discovering Men. Persuaded by Melkor, Men stop worshipping Eru Ilúvatar and turn to evil, but some revolt: the Atanatári. These travel to the West in search for the Valar, aided by AvariElves and Dwarves. According to legend, Men now lose the gift to dieat will as the result of divine punishment, and are doomed to lead short life-spans at the end of which death takes them by force.[3]

465: Beren sets on a Quest of the Silmaril, comes to Nargothrond and receives help of Finrod Felagund. They are imprisoned in Tol-in-Gaurhoth. Finrod is slain by a werewolf, but Beren is rescued by Lúthien. Celegorm and Curufin are exiled from Nargothrond and attempt to attack Beren and Lúthien, but fail. Celebrimbor the son of Curufin rejects the deeds of his father and stays in Nargothrond.

466: Birth of Lalaith in the beginning of spring.[9]Beren and Lúthien come to Angband and achieve the Quest of the Silmaril. They return to Doriath, but Carcharoth ravages the land. Beren dies, and Lúthien abandons life. She pleads with Mandos and Beren and Lúthien are restored to life as mortals; they take up bodies again in Ossiriand.

489: In autumn Amon Rûdh is taken; Túrin captured, but is rescued by Gwindor and Beleg, and slays the latter.

490: In the beginning of year Túrin is healed at Eithel Ivrin, comes to Nargothrond. Gurthang is reforged, Túrin becomes known as the Blacksword.

494: In autumn Morwen and Nienor flee to Doriath.

495: Fall of Nargothrond in autumn; Gwindor, Orodreth and his daughter Finduilas perish, but his son Gil-galad escapes with Celebrimbor. In the beginning of winter Túrin passes Ivrin; Tuor comes to Nevrast.

496: Túrin rises a revolt in Dor-lómin;[11] in the beginning of spring he comes to Brethil, Morwen with Nienor journey to Nargothrond; Níniel comes to Brethil. Tuor arrives at Gondolin.

From this point the entries are derived from The Tale of Years of the First Age (see references) unless otherwise noted.

502: Reforging of the Nauglamír and quarrel of Thingol and the Dwarves. Thingol is slain.[12]Melian returns to Valinor in grief.

503: Doriath is sacked by Dwarves of Nogrod. Beren and the Laiquendi destroy the Dwarves, with the help of the Ents who prevent the Dwarves' escape; Lúthien receives and wears the Silmaril, Dior travels to Doriath and tries to restore it. Birth of Eärendil and Elwing. Final deaths of Beren and Lúthien; Dior receives the Silmaril in autumn.

506–7: Sons of Fëanor attack Doriath at Yule. Doriath is destroyed in the Second Kinslaying; Dior, Nimloth, Celegorm, Curufin, and Caranthir are all slain, and Eluréd and Elurín are abandoned to die by the cruel servants of Celegorm. Maedhros searches for them, but does not find them. Elwing escapes for the Mouths of Sirion with the Silmaril.

538: Third Kinslaying: while Eärendil is away the remaining Sons of Fëanor attack the people of the Mouths of Sirion trying to claim the Silmaril. Elwing casts herself with the Jewel in the sea but is brought to Eärendil upon Vingilótë by Ulmo. Death of Amras. Of the Sons of Fëanor only Maedhros and Maglor now remain. Maglor takes Elrond and Elros captive and raises them.

540: Morgoth destroys the dwellings of Fëanorians upon Amon Ereb. The last inhabitants of Beleriand flee to the south or to the Isle of Balar. Morgoth's triumph is complete.

542: Eärendil arrives in Valinor and delivers the errand of the Two Kindreds.

587: Ancalagon killed by Eärendil. Morgoth is defeated; the remaining two Silmarils are stolen by Maedhros and Maglor, but are lost in the earth and in the sea; suicide of Maedhros;[14] most of Beleriand and the lands to the north are sunk.

590: Morgoth is cast into the Void; the Elves are summoned to Valinor and settle in Tol Eressëa; a small part of the Noldor and Sindar remain in Lindon (previously part of Ossiriand) or depart east and establish realms.

1075: Tar-Ancalimë becomes the first Queen and seventh ruler of Númenor.

c. 1200: Sauron seduces and deceives the Noldor in Eregion, but Gil-galad mistrusts him and refuses to work with him; the Númenóreans begin building permanent havens in Middle-earth at Lond Daer, Umbar, and other places

3262: Sauron is taken as prisoner to Númenor, but begins corrupting the Númenóreans

c. 3265: Sauron becomes Ar-Pharazôn's court advisor.

c. 3280: Isildur steals a fruit from Nimloth. The White Tree is felled and burnt in Sauron's Temple thereafter.

c. 3300: Sauron establishes himself as High Priest of Melkor, "Lord of the Dark"; Elendili are openly persecuted and sacrificed to Morgoth

3310: At Sauron's instigation, Ar-Pharazôn begins building the Great Armament.

3318: Birth of Meneldil, fourth child of Anárion and last man born in Númenor

3319: Ar-Pharazôn sets foot on Aman; the World is Changed: Aman and Tol Eressëa are removed from Arda, Númenor is drowned, and the world is made round; Elendil and his sons arrive on the shores of Middle-earth

3441: Elendil and Gil-galad face Sauron in hand-to-hand combat, but they themselves perish; Isildur takes the shards of his father's sword Narsil and cuts the One Ring from Sauron's finger. Sauron's physical form is destroyed and the Barad-dûr is razed to the ground. In the aftermath of the War, many Elves of Gil-galad's following depart to Valinor: end of the Noldorin realms in Middle-earth.

The Third Age was 3,021 years long. All entries are derived from Appendix B (see references) unless otherwise noted.

Note on Shire Reckoning: Year 1601 of the Third Age, in which the Shire was founded, is year 1 of the Shire Reckoning. Thus, Third Age years can be converted into their Shire equivalents by deducting 1600.

1409: Cardolan is conquered by the kingdom of Angmar, and Rhudaur disappears; Weathertop watchtower and fortifications are burned and destroyed. Annúminas is attacked, sacked and abandoned in ruins until the Fourth Age.

2510: The alliance between Rohan and Gondor comes into existence. The Easterlings launch a massive invasion of Gondor. The Balchoth invade Rhovanion (which disappears as an independent realm) and Gondor, conquering much of Calenardhon, but are driven back by the people of Éothéod; Gondor gives the now-uninhabited province of Calenardhon to the people of Éothéod

2545: Eorl the Young, king of Rohan, dies in the battle in the Wold against the Easterlings. Brego succeeds him as the second king of Rohan

2570: Aldor, aged only 26, becomes third king of Rohan on the death of his father Brego; Dragons attack the Dwarf settlements in the Grey Mountains

2759: Helm Hammerhand, king of Rohan, freezes to death outside the fortress of Helm's Deep, where he and his loyal subjects have taken refuge from the Dunlendings. He is succeeded by his nephew Fréaláf Hildeson; Saruman settles in Isengard

2770: Smaug lays waste to the town of Dale and captures Erebor with all of its treasure. The surviving Dwarves there are driven into exile.

'March' 15: Witch-king breaks the gate of Minas Tirith in the early hours. Denethor burns himself on a pyre. Confrontation between Gandalf and the Witch-king at the gate; Horns of the Rohirrim are heard at a cockcrow. Battle of the Pelennor Fields: Théoden King of Rohan is killed by the Witch-king; Éomer succeeds him as the eighteenth king of Rohan. Éowyn and Merry kill the Witch-king. Aragorn, Rangers, the sons of Elrond and men from the southern fiefdoms of Gondor arrive in the black ships and turn the tide of battle. Sam and Frodo escape and journey along the Morgai. Battle under the trees in Mirkwood; second assault on Lórien.

'March' 16: Debate of the Captains of the West.

'March' 17: Battle of Dale. King Brand and Dáin Ironfoot fall in battle against invading Easterlings. Many Men and Dwarves take refuge in Erebor.

'March' 25: The Host is surrounded on the slag-hills. Frodo and Sam reach the Sammath Naur. Gollum (Sméagol) seizes the One Ring and falls into the Cracks of Doom. Downfall of Barad-dûr and the passing of the Dark Lord Sauron.

'March' 28: Celeborn leads his forces in the attack and destruction of the fortress of Dol Guldur. Galadriel throws down its walls to cleanse Mirkwood of its evil.

Length uncertain. All entries are derived from the Appendices to The Lord of the Rings, unless otherwise noted.

In the reckoning of Gondor, the Fourth Age began on 'March' 25, T.A. 3021. Since most of the following events had been dated according to the Shire-reckoning, their years in the Fourth Age cannot be stated with certainty. Some events may have occurred in the following year of the Fourth Age.

120: Death of Aragorn, King of the Reunited Kingdom of Arnor and Gondor, after 210 years of life and 122 years of reign; his son Eldarion ascends the throne. The bodies of Meriadoc and Peregrin are laid beside that of Aragorn. According to legend, on the death of Aragorn, Legolas builds a ship and sails into the west to the Undying Lands, taking Gimli (now a very old Dwarf) with him and marking an end to the Fellowship of the Ring.

^in a letter written in 1958, published in Carpenter, Humphrey, ed. (1981), The Letters of J. R. R. Tolkien, Boston: Houghton Mifflin, #211, ISBN 0-395-31555-7, Tolkien places the beginning of the Fourth Age some 6,000 years in the past, consistent with the scope of classical historiography reaching back to just after the beginning Dominion of Men: "I imagine the gap [since the end of the Third Age] to be about 6000 years; that is we are now at the end of the Fifth Age, if the Ages were of about the same length as S[econd] A[ge] and T[hird] A[ge]. But they have, I think, quickened; and I imagine we are actually at the end of the Sixth Age, or in the Seventh."

^"Time indeed began with the beginning of Eä, and in that beginning the Valar came into the world. But the measurement which the Valar made of the ages of their labours is not known to any of the Children of Ilúvatar, until the first flowering of Telperion in Valinor. Thereafter the Valar counted time by the ages of Valinor, whereof each age contained one hundred of the Years of the Valar; but each such year was longer than are now nine years under the Sun."Tolkien, Christopher; Tolkien, J.R.R. (1993). Morgoth's Ring (First ed.). Boston and New York: Houghton Mifflin Company. p. Frontispiece illustration (calligraphy). ISBN0-395-68092-1.

^The dates of the entering of the Second and Third Houses are given as 312 and 313 respectively in the Later Quenta Silmarillion, but as (?312/313) and 314 in later notes. (The War of the Jewels, pp. 227, 234)

^The date of the entering to Brethil is only once given (in Grey Annals, The War of the Jewels p. 50), as 422; but according to later sources Haleth, who is stated to had led them there, died in 420. (ibid. p. 228, 237)

^The War of the Jewels: "The new genealogies of the Edain", p. 229–38.

^The taking of Tol Sirion is given under the year 455 in the Grey Annals (The War of the Jewels p. 54). The statement in The Silmarillion (Ch. 18) that it occurred "nearly two years" after the Dagor Bragollach derives from earlier texts without changes and represents rejected chronology: see The War of the Jewels, p. 125.

^The statements in The Silmarillion and The Children of Húrin that Túrin had dwelt in Doriath for nine years by this time derive from the early Quenta Silmarillion (The Lost Road, p. 320–2), and are contradicted by both earlier and later texts (e.g. The Grey Annals, pp. 79–80).

^ abcdeThe War of the Jewels: "The Wanderings of Húrin", p. 257, gives a plot-synopsis for the Narn i Chîn Húrin, written several years later than the concluding chapters of the story itself; the published Unfinished Tales and The Children of Húrin are based on the latter.

^The death of Thingol is placed under the year 503 in The Tale of Years, but according to the story introduced into The Silmarillion by Christopher Tolkien it should have rather occurred immediately after the reforging of Nauglamír, while the Sack of Doriath remained in the following year.

^Silmariën was definitely the eldest child of Tar-Elendil, and her birthdate is given several times as S.A. 521. In the Tale of Years, the entry of Silmariën's birthdate is given as 548, a date that goes back to the first drafts of that text (see Silmariën's article for details).

^In the Tale of years, it says in S.A. 2251 "Tar-Atanamir takes the sceptre", however, Atanamir died in 2221. 2221 is itself an emendation of 2251, and the former (2221) appears in the later tables, while the latter (2251) in the earlier tables: therefore 2251 (properly 2221) should have read "Death of Tar-Atanamir. Tar-Ancalimon takes the sceptre."

^In one table (probably an earlier draft) of the Kings of Gondor, Castamir's birthdate is given at T.A. 1159, however this is clearly impossible: Eldacar was born in 1255, and they are in the same generation, so 1259 is more correct.

^The date of Sam's birth in "The Longfather-Tree of Master Samwise" (Appendix C) is S.R. 1380 (equivalent to T.A. 2980), however, "The Tale of Years" (Appendix B) gives it as T.A. 2983, which is changed to T.A. 2980 in 2005 edition. In S.R. 1476, Sam is said to have been ninety-six years old, so 2980 is more correct than 2983. Also, the birth year of his sister, Marigold, is given S.R. 1383 (T.A. 2893), and it is most unlikely that they were born in the same year. In The Fellowship of the Ring, Merry and Pippin is said to be younger than both Sam and Frodo, so Sam's birth year must be in T.A. 2980, since Merry was born in T.A. 2982.

^In a 1972 letter, Tolkien mentioned that Eldarion's reign would have lasted for about 100 years after the death of Aragorn. Carpenter, Humphrey, ed. (1981), The Letters of J. R. R. Tolkien, Boston: Houghton Mifflin, #338. "I have written nothing beyond the first few years of the Fourth Age. (Except the beginning of a tale supposed to refer to the end of the reign of Eldarion about 100 years after the death of Aragorn. ...)", ISBN 0-395-31555-7